Alterações fisiológicas e bioquímicas em sementes de amendoim (Arachis hypogaea L.)

Abstract

Groundnut (Arachis hypogaea L.) is an oleaginous plant of significant economic importance, much used for in natura consumption, in the food industries and in planting systems, and can be cultivated in all regions of Brazil. In the Northeast it is notable for adapting the climatic conditions that favor the reduction of its cycle, being easy to handle and a source of income for small producers. However, there is scarce information on the characteristics of cultivars in the region regarding their vigor and behavior during accelerated aging. The objective of this work was to study the physiological and biochemical changes in aged peanut seeds. Seeds of two cultivars were used for the experiments: IAC Tatu ST and Caiana, both aged artificially at 42 ºC and 100% relative humidity up to 96 hours. The water content, the weight of one thousand seeds and the oil content were initially evaluated. Before and after each 24 hours of aging, seeds were collected for physiological tests (germination, germination rate index, first count, seedlings and cotyledons) and biochemistry (conductivity (TC) and Ascorbate Peroxidase (APX). The seeds of the cultivars Tatu and Caiana present significant differences initially in the weight of a thousand seeds, water content and oil.With accelerated aging, a reduction in the first count occurred , the rate of germination, germination, lengths and dry mass of the seedlings, while significantly increasing the amount of leached electrolytes, the total activity of the APX was not altered during the treatment of seeds of the Caiana cultivar. significant changes in CAT content in both cultivars during the aging, the seeds of the cultivar Tatu are more resistant to the damages induced by aging when compared to the Caiana.